<?php
// +----------------------------------------------------------------------
// | Kses PHP HTML 适配 THINKPHP过滤类
// +----------------------------------------------------------------------
// | Copyright (c) 2014 http://www.onlyke.com All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: metaur ( http://sourceforge.net/projects/kses/ )
// +----------------------------------------------------------------------
// | Editor: mysunck <mysunck@163.com>
// +----------------------------------------------------------------------

/**
 * 修改日志 ( 2014-4-13 )
 * 1. 增加命名空间，和配置等以适应THINKPHP
 * 2. 修改类名。
 * 3. 2014-4-13 01:21:01 修正参数名称BUG一个。
 * 4. 增加了全局属性，以及CSS检测
 *
 * 说明文档：http://www.thinkphp.cn/code/624.html
 *
 */

namespace vm\org;

/*
 * ==========================================================================================
 *
 * This program is free software and open source software; you can redistribute
 * it and/or modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the License,
 * or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA  or visit
 * http://www.gnu.org/licenses/gpl.html
 *
 * ==========================================================================================
 */

/**
 *	Class file for PHP5 OOP version of kses
 *
 *	This is an updated version of kses to work with PHP5 that works under E_STRICT.
 *
 *	This version is a bit of a rewrite to match my own coding style and use some of the
 *	capabilities allowed in PHP5.  Since this was a significant rewrite, but it still
 *	maintains backward compatibility syntax-wise, the version number is now 1.0.0.  Any
 *	minor changes that do not break compatibility will be indicated in the second or third
 *	digits.  Anything that breaks compatibility will change the major version number.
 *
 *	PHP5 specific changes:
 *	+ Private methods are now in place
 *	+ __construct() is now used rather then the standard class name 'kses()'
 *	+ Kses will not load in any version less that PHP5
 *	Other modifications:
 *	+ PHPdoc style documentation has been added to the class.  See http://www.phpdoc.org/ for more info.
 *	+ Method names have been changed to reflect status as verbs
 *	+ One line methods have been folded into the code
 *	+ Some methods are now deprecated due to nomenclature style change.  See method documentation for specifics.
 *	+ Kses now works in E_STRICT
 *	+ Version number is 1.0.0 to reflect serious code changes
 *	+ Addition of methods AddProtocols(), filterKsestextHook(), RemoveProtocol(), RemoveProtocols() and SetProtocols()
 *	+ Deprecated _hook(), Protocols()
 *
 *	@package    kses
 *	@subpackage Kses
 */


/**
 *	Kses strips evil scripts!
 *
 *	This class provides the capability for removing unwanted HTML/XHTML, attributes from
 *	tags, and protocols contained in links.  The net result is a much more powerful tool
 *	than the PHP internal strip_tags()
 *
 *	This is a fork of a slick piece of procedural code called 'kses' written by Ulf Harnhammar.
 *
 *	The original class for PHP4 was basically a wrapper around all of the functions in
 *	the procedural code written by Ulf, and was released 7/25/2003.
 *
 *	This version is a bit of a rewrite to match my own coding style and use some of the
 *	capabilities allowed in PHP5.  Since this was a significant rewrite, but it still
 *	maintains backward compatibility syntax-wise, the version number is now 1.0.0.  Any
 *	minor changes that do not break compatibility will be indicated in the second or third
 *	digits.  Anything that breaks compatibility will change the major version number.
 *
 *	PHP5 specific changes:
 *	+ Private methods are now in place
 *	+ __construct() is now used rather then the standard class name 'kses()'
 *	+ Kses will not load in any version less that PHP5
 *	Other modifications:
 *	+ PHPdoc style documentation has been added to the class.  See http://www.phpdoc.org/ for more info.
 *	+ Method names have been changed to reflect status as verbs
 *	+ One line methods have been folded into the code
 *	+ Some methods are now deprecated due to nomenclature style change.  See method documentation for specifics.
 *	+ Kses now works in E_STRICT
 *	+ Initial Version number set to 1.0.0 to reflect serious code changes
 *	+ Addition of methods AddProtocols(), filterKsestextHook(), RemoveProtocol(), RemoveProtocols() and SetProtocols()
 *	+ Deprecated _hook(), Protocols()
 *	+ Integrated code from kses 0.2.2 into class.
 *	+ Added methods DumpProtocols(), DumpMethods()
 *
 *	@author     Richard R. Vásquez, Jr. (Original procedural code by Ulf Härnhammar)
 *	@link       http://sourceforge.net/projects/kses/ Home Page for Kses
 *	@link       http://chaos.org/contact/ Contact page with current email address for Richard Vasquez
 *	@copyright  Richard R. Vásquez, Jr. 2005
 *	@version    PHP5 OOP 1.0.2
 *	@license    http://www.gnu.org/licenses/gpl.html GNU Public License
 *	@package    kses
 */
class Kses
{
    /**#@+
     *	@access private
     *	@var array
     */
    private $allowed_protocols;
    private $allowed_html;
    private $allowed_global_attr;
    /**#@-*/

    /**
     *	Constructor for kses.
     *
     *	This sets a default collection of protocols allowed in links, and creates an
     *	empty set of allowed HTML tags.
     *	@since PHP5 OOP 1.0.0
     */
    public function __construct()
    {
        /**
         *	You could add protocols such as ftp, new, gopher, mailto, irc, etc.
         *
         *	The base values the original kses provided were:
         *		'http', 'https', 'ftp', 'news', 'nntp', 'telnet', 'gopher', 'mailto'
         */
        //$this->allowed_protocols = array('http', 'ftp', 'mailto');
        //$this->allowed_html      = array();

        $this->allowed_protocols =  C('KSES_ALLOWED_PROTOCOL');
        $this->allowed_html = C('KSES_ALLOWED_HTML');
        $global_attr = C('KSES_ALLOWED_GLOBAL_ATTR');
        if(is_array($global_attr) && count($global_attr) > 0){
            $this->allowed_global_attr = $global_attr;
            $this->allowed_html = array_map(array(__CLASS__,'add_global_attr'), $this->allowed_html);
        }
    }

    private function add_global_attr($value){
        if ($value === true)
            $value = array();
        if (is_array($value))
            return array_merge($value, $this->allowed_global_attr);
        return $value;
    }

    /**
     *	Basic task of kses - parses $string and strips it as required.
     *
     *	This method strips all the disallowed (X)HTML tags, attributes
     *	and protocols from the input $string.
     *
     *	@access public
     *	@param string $string String to be stripped of 'evil scripts'
     *	@return string The stripped string
     *	@since PHP4 OOP 0.0.1
     */
    public function Parse($string = "")
    {
        if (get_magic_quotes_gpc())
        {
            $string = stripslashes($string);
        }
        $string = $this->removeNulls($string);
        //	Remove JavaScript entities from early Netscape 4 versions
        $string = preg_replace('%&\s*\{[^}]*(\}\s*;?|$)%', '', $string);
        $string = $this->normalizeEntities($string);
        $string = $this->filterKsesTextHook($string);
        $string = preg_replace('%(<' . '[^>]*' . '(>|$)' . '|>)%e', "\$this->stripTags('\\1')", $string);
        return $string;
    }

    /**
     *	Allows for single/batch addition of protocols
     *
     *	This method accepts one argument that can be either a string
     *	or an array of strings.  Invalid data will be ignored.
     *
     *	The argument will be processed, and each string will be added
     *	via AddProtocol().
     *
     *	@access public
     *	@param mixed , A string or array of protocols that will be added to the internal list of allowed protocols.
     *	@return bool Status of adding valid protocols.
     *	@see AddProtocol()
     *	@since PHP5 OOP 1.0.0
     */
    public function AddProtocols()
    {
        $c_args = func_num_args();
        if($c_args != 1)
        {
            trigger_error("Kses::AddProtocols() did not receive an argument.", E_USER_WARNING);
            return false;
        }

        $protocol_data = func_get_arg(0);

        if(is_array($protocol_data) && count($protocol_data) > 0)
        {
            foreach($protocol_data as $protocol)
            {
                $this->AddProtocol($protocol);
            }
            return true;
        }
        elseif(is_string($protocol_data))
        {
            $this->AddProtocol($protocol_data);
            return true;
        }
        else
        {
            trigger_error("Kses::AddProtocols() did not receive a string or an array.", E_USER_WARNING);
            return false;
        }
    }

    /**
     *	Allows for single/batch addition of protocols
     *
     *	@deprecated Use AddProtocols()
     *	@see AddProtocols()
     *	@return bool
     *	@since PHP4 OOP 0.0.1
     */
    public function Protocols()
    {
        $c_args = func_num_args();
        if($c_args != 1)
        {
            trigger_error("Kses::Protocols() did not receive an argument.", E_USER_WARNING);
            return false;
        }

        return $this->AddProtocols(func_get_arg(0));
    }

    /**
     *	Adds a single protocol to $this->allowed_protocols.
     *
     *	This method accepts a string argument and adds it to
     *	the list of allowed protocols to keep when performing
     *	Parse().
     *
     *	@access public
     *	@param string $protocol The name of the protocol to be added.
     *	@return bool Status of adding valid protocol.
     *	@since PHP4 OOP 0.0.1
     */
    public function AddProtocol($protocol = "")
    {
        if(!is_string($protocol))
        {
            trigger_error("Kses::AddProtocol() requires a string.", E_USER_WARNING);
            return false;
        }

        // Remove any inadvertent ':' at the end of the protocol.
        if(substr($protocol, strlen($protocol) - 1, 1) == ":")
        {
            $protocol = substr($protocol, 0, strlen($protocol) - 1);
        }

        $protocol = strtolower(trim($protocol));
        if($protocol == "")
        {
            trigger_error("Kses::AddProtocol() tried to add an empty/NULL protocol.", E_USER_WARNING);
            return false;
        }

        //	prevent duplicate protocols from being added.
        if(!in_array($protocol, $this->allowed_protocols))
        {
            array_push($this->allowed_protocols, $protocol);
            sort($this->allowed_protocols);
        }
        return true;
    }

    /**
     *	Removes a single protocol from $this->allowed_protocols.
     *
     *	This method accepts a string argument and removes it from
     *	the list of allowed protocols to keep when performing
     *	Parse().
     *
     *	@access public
     *	@param string $protocol The name of the protocol to be removed.
     *	@return bool Status of removing valid protocol.
     *	@since PHP5 OOP 1.0.0
     */
    public function RemoveProtocol($protocol = "")
    {
        if(!is_string($protocol))
        {
            trigger_error("Kses::RemoveProtocol() requires a string.", E_USER_WARNING);
            return false;
        }

        // Remove any inadvertent ':' at the end of the protocol.
        if(substr($protocol, strlen($protocol) - 1, 1) == ":")
        {
            $protocol = substr($protocol, 0, strlen($protocol) - 1);
        }

        $protocol = strtolower(trim($protocol));
        if($protocol == "")
        {
            trigger_error("Kses::RemoveProtocol() tried to remove an empty/NULL protocol.", E_USER_WARNING);
            return false;
        }

        //	Ensures that the protocol exists before removing it.
        if(in_array($protocol, $this->allowed_protocols))
        {
            $this->allowed_protocols = array_diff($this->allowed_protocols, array($protocol));
            sort($this->allowed_protocols);
        }

        return true;
    }

    /**
     *	Allows for single/batch removal of protocols
     *
     *	This method accepts one argument that can be either a string
     *	or an array of strings.  Invalid data will be ignored.
     *
     *	The argument will be processed, and each string will be removed
     *	via RemoveProtocol().
     *
     *	@access public
     *	@param mixed , A string or array of protocols that will be removed from the internal list of allowed protocols.
     *	@return bool Status of removing valid protocols.
     *	@see RemoveProtocol()
     *	@since PHP5 OOP 1.0.0
     */
    public function RemoveProtocols()
    {
        $c_args = func_num_args();
        if($c_args != 1)
        {
            return false;
        }

        $protocol_data = func_get_arg(0);

        if(is_array($protocol_data) && count($protocol_data) > 0)
        {
            foreach($protocol_data as $protocol)
            {
                $this->RemoveProtocol($protocol);
            }
        }
        elseif(is_string($protocol_data))
        {
            $this->RemoveProtocol($protocol_data);
            return true;
        }
        else
        {
            trigger_error("Kses::RemoveProtocols() did not receive a string or an array.", E_USER_WARNING);
            return false;
        }
    }

    /**
     *	Allows for single/batch replacement of protocols
     *
     *	This method accepts one argument that can be either a string
     *	or an array of strings.  Invalid data will be ignored.
     *
     *	Existing protocols will be removed, then the argument will be
     *	processed, and each string will be added via AddProtocol().
     *
     *	@access public
     *	@param mixed , A string or array of protocols that will be the new internal list of allowed protocols.
     *	@return bool Status of replacing valid protocols.
     *	@since PHP5 OOP 1.0.1
     *	@see AddProtocol()
     */
    public function SetProtocols()
    {
        $c_args = func_num_args();
        if($c_args != 1)
        {
            trigger_error("Kses::SetProtocols() did not receive an argument.", E_USER_WARNING);
            return false;
        }

        $protocol_data = func_get_arg(0);

        if(is_array($protocol_data) && count($protocol_data) > 0)
        {
            $this->allowed_protocols = array();
            foreach($protocol_data as $protocol)
            {
                $this->AddProtocol($protocol);
            }
            return true;
        }
        elseif(is_string($protocol_data))
        {
            $this->allowed_protocols = array();
            $this->AddProtocol($protocol_data);
            return true;
        }
        else
        {
            trigger_error("Kses::SetProtocols() did not receive a string or an array.", E_USER_WARNING);
            return false;
        }
    }

    /**
     *	Raw dump of allowed protocols
     *
     *	This returns an indexed array of allowed protocols for a particular KSES
     *	instantiation.
     *
     *	@access public
     *	@return array The list of allowed protocols.
     *	@since PHP5 OOP 1.0.2
     */
    public function DumpProtocols()
    {
        return $this->allowed_protocols;
    }

    /**
     *	Raw dump of allowed (X)HTML elements
     *
     *	This returns an indexed array of allowed (X)HTML elements and attributes
     *	for a particular KSES instantiation.
     *
     *	@access public
     *	@return array The list of allowed elements.
     *	@since PHP5 OOP 1.0.2
     */
    public function DumpElements()
    {
        return $this->allowed_html;
    }


    /**
     *	Adds valid (X)HTML with corresponding attributes that will be kept when stripping 'evil scripts'.
     *
     *	This method accepts one argument that can be either a string
     *	or an array of strings.  Invalid data will be ignored.
     *
     *	@access public
     *	@param string $tag (X)HTML tag that will be allowed after stripping text.
     *	@param array $attribs Associative array of allowed attributes - key => attribute name - value => attribute parameter
     *	@return bool Status of Adding (X)HTML and attributes.
     *	@since PHP4 OOP 0.0.1
     */
    public function AddHTML($tag = "", $attribs = array())
    {
        if(!is_string($tag))
        {
            trigger_error("Kses::AddHTML() requires the tag to be a string", E_USER_WARNING);
            return false;
        }

        $tag = strtolower(trim($tag));
        if($tag == "")
        {
            trigger_error("Kses::AddHTML() tried to add an empty/NULL tag", E_USER_WARNING);
            return false;
        }

        if(!is_array($attribs))
        {
            trigger_error("Kses::AddHTML() requires an array (even an empty one) of attributes for '$tag'", E_USER_WARNING);
            return false;
        }

        $new_attribs = array();
        if(is_array($attribs) && count($attribs) > 0)
        {
            foreach($attribs as $idx1 => $val1)
            {
                $new_idx1 = strtolower($idx1);
                $new_val1 = $attribs[$idx1];

                if(is_array($new_val1) && count($attribs) > 0)
                {
                    $tmp_val = array();
                    foreach($new_val1 as $idx2 => $val2)
                    {
                        $new_idx2 = strtolower($idx2);
                        $tmp_val[$new_idx2] = $val2;
                    }
                    $new_val1 = $tmp_val;
                }

                $new_attribs[$new_idx1] = $new_val1;
            }
        }

        $this->allowed_html[$tag] = $new_attribs;
        return true;
    }

    /**
     *	This method removes any NULL characters in $string.
     *
     *	@access private
     *	@param string $string
     *	@return string String without any NULL/chr(173)
     *	@since PHP4 OOP 0.0.1
     */
    private function removeNulls($string)
    {
        $string = preg_replace('/\0+/', '', $string);
        $string = preg_replace('/(\\\\0)+/', '', $string);
        return $string;
    }

    /**
     *	Normalizes HTML entities
     *
     *	This function normalizes HTML entities. It will convert "AT&T" to the correct
     *	"AT&amp;T", "&#00058;" to "&#58;", "&#XYZZY;" to "&amp;#XYZZY;" and so on.
     *
     *	@access private
     *	@param string $string
     *	@return string String with normalized entities
     *	@since PHP4 OOP 0.0.1
     */
    private function normalizeEntities($string)
    {
        # Disarm all entities by converting & to &amp;
        $string = str_replace('&', '&amp;', $string);

        #	TODO: Change back (Keep?) the allowed entities in our entity white list

        #	Keeps entities that start with [A-Za-z]
        $string = preg_replace(
            '/&amp;([A-Za-z][A-Za-z0-9]{0,19});/',
            '&\\1;',
            $string
        );

        #	Change numeric entities to valid 16 bit values

        $string = preg_replace(
            '/&amp;#0*([0-9]{1,5});/e',
            '\$this->normalizeEntities16bit("\\1")',
            $string
        );

        #	Change &XHHHHHHH (Hex digits) to 16 bit hex values
        $string = preg_replace(
            '/&amp;#([Xx])0*(([0-9A-Fa-f]{2}){1,2});/',
            '&#\\1\\2;',
            $string
        );

        return $string;
    }

    /**
     *	Helper method used by normalizeEntites()
     *
     *	This method helps normalizeEntities() to only accept 16 bit values
     *	and nothing more for &#number; entities.
     *
     *	This method helps normalize_entities() during a preg_replace()
     *	where a &#(0)*XXXXX; occurs.  The '(0)*XXXXXX' value is converted to
     *	a number and the result is returned as a numeric entity if the number
     *	is less than 65536.  Otherwise, the value is returned 'as is'.
     *
     *	@access private
     *	@param string $i
     *	@return string Normalized numeric entity
     *	@see normalizeEntities()
     *	@since PHP4 OOP 0.0.1
     */
    private function normalizeEntities16bit($i)
    {
        return (($i > 65535) ? "&amp;#$i;" : "&#$i;");
    }

    /**
     *	Allows for additional user defined modifications to text.
     *
     *	This method allows for additional modifications to be performed on
     *	a string that's being run through Parse().  Currently, it returns the
     *	input string 'as is'.
     *
     *	This method is provided for users to extend the kses class for their own
     *	requirements.
     *
     *	@access public
     *	@param string $string String to perfrom additional modifications on.
     *	@return string User modified string.
     *	@see Parse()
     *	@since PHP5 OOP 1.0.0
     */
    private function filterKsesTextHook($string)
    {
        return $string;
    }

    /**
     *	Allows for additional user defined modifications to text.
     *
     *	@deprecated use filterKsesTextHook()
     *	@param string $string
     *	@return string
     *	@see filterKsesTextHook()
     *	@since PHP4 OOP 0.0.1
     */
    private function _hook($string)
    {
        return $this->filterKsesTextHook($string);
    }

    /**
     *	This method goes through an array, and changes the keys to all lower case.
     *
     *	@access private
     *	@param array $in_array Associative array
     *	@return array Modified array
     *	@since PHP4 OOP 0.0.1
     */
    private function makeArrayKeysLowerCase($in_array)
    {
        $out_array = array();

        if(is_array($in_array) && count($in_array) > 0)
        {
            foreach ($in_array as $in_key => $in_val)
            {
                $out_key = strtolower($in_key);
                $out_array[$out_key] = array();

                if(is_array($in_val) && count($in_val) > 0)
                {
                    foreach ($in_val as $in_key2 => $in_val2)
                    {
                        $out_key2 = strtolower($in_key2);
                        $out_array[$out_key][$out_key2] = $in_val2;
                    }
                }
            }
        }

        return $out_array;
    }

    /**
     *	This method strips out disallowed and/or mangled (X)HTML tags along with assigned attributes.
     *
     *	This method does a lot of work. It rejects some very malformed things
     *	like <:::>. It returns an empty string if the element isn't allowed (look
     *	ma, no strip_tags()!). Otherwise it splits the tag into an element and an
     *	allowed attribute list.
     *
     *	@access private
     *	@param string $string
     *	@return string Modified string minus disallowed/mangled (X)HTML and attributes
     *	@since PHP4 OOP 0.0.1
     */
    private function stripTags($string)
    {
        $string = preg_replace('%\\\\"%', '"', $string);

        if (substr($string, 0, 1) != '<')
        {
            # It matched a ">" character
            return '&gt;';
        }

        if (!preg_match('%^<\s*(/\s*)?([a-zA-Z0-9]+)([^>]*)>?$%', $string, $matches))
        {
            # It's seriously malformed
            return '';
        }

        $slash    = trim($matches[1]);
        $elem     = $matches[2];
        $attrlist = $matches[3];

        if (
            !isset($this->allowed_html[strtolower($elem)]) ||
            !is_array($this->allowed_html[strtolower($elem)]))
        {
            #	Found an HTML element not in the white list
            return '';
        }

        if ($slash != '')
        {
            return "<$slash$elem>";
        }
        # No attributes are allowed for closing elements

        return $this->stripAttributes("$slash$elem", $attrlist);
    }

    /**
     *	This method strips out disallowed attributes for (X)HTML tags.
     *
     *	This method removes all attributes if none are allowed for this element.
     *	If some are allowed it calls combAttributes() to split them further, and then it
     *	builds up new HTML code from the data that combAttributes() returns. It also
     *	removes "<" and ">" characters, if there are any left. One more thing it
     *	does is to check if the tag has a closing XHTML slash, and if it does,
     *	it puts one in the returned code as well.
     *
     *	@access private
     *	@param string $element (X)HTML tag to check
     *	@param string $attr Text containing attributes to check for validity.
     *	@return string Resulting valid (X)HTML or ''
     *	@see combAttributes()
     *	@since PHP4 OOP 0.0.1
     */
    private function stripAttributes($element, $attr)
    {
        # Is there a closing XHTML slash at the end of the attributes?
        $xhtml_slash = '';
        if (preg_match('%\s/\s*$%', $attr))
        {
            $xhtml_slash = ' /';
        }

        # Are any attributes allowed at all for this element?
        if (
            !isset($this->allowed_html[strtolower($element)]) ||
            count($this->allowed_html[strtolower($element)]) == 0
        )
        {
            return "<$element$xhtml_slash>";
        }

        # Split it
        $attrarr = $this->combAttributes($attr);

        # Go through $attrarr, and save the allowed attributes for this element
        # in $attr2
        $attr2 = '';
        if(is_array($attrarr) && count($attrarr) > 0)
        {
            foreach ($attrarr as $arreach)
            {
                if(!isset($this->allowed_html[strtolower($element)][strtolower($arreach['name'])]))
                {
                    continue;
                }

                $current = $this->allowed_html[strtolower($element)][strtolower($arreach['name'])];

                if (strtolower( $arreach['name'] ) == 'style')
                {

                    $orig_value = $arreach['value'];
                    $value = $this->safecss_filter_attr($orig_value);

                    if (empty($value))
                        continue;

                    $arreach['value'] = $value;
                    $arreach['whole'] = str_replace( $orig_value, $value, $arreach['whole'] );
                }


                if (!is_array($current))
                {
                    # there are no checks
                    $attr2 .= ' '.$arreach['whole'];
                }
                else
                {
                    # there are some checks
                    $ok = true;
                    if(is_array($current) && count($current) > 0)
                    {
                        foreach ($current as $currkey => $currval)
                        {
                            if (!$this->checkAttributeValue($arreach['value'], $arreach['vless'], $currkey, $currval))
                            {
                                $ok = false;
                                break;
                            }
                        }
                    }

                    if ($ok)
                    {
                        # it passed them
                        $attr2 .= ' '.$arreach['whole'];
                    }
                }
            }
        }

        # Remove any "<" or ">" characters
        $attr2 = preg_replace('/[<>]/', '', $attr2);
        return "<$element$attr2$xhtml_slash>";
    }

    /**
     *	This method combs through an attribute list string and returns an associative array of attributes and values.
     *
     *	This method does a lot of work. It parses an attribute list into an array
     *	with attribute data, and tries to do the right thing even if it gets weird
     *	input. It will add quotes around attribute values that don't have any quotes
     *	or apostrophes around them, to make it easier to produce HTML code that will
     *	conform to W3C's HTML specification. It will also remove bad URL protocols
     *	from attribute values.
     *
     *	@access private
     *	@param string $attr Text containing tag attributes for parsing
     *	@return array Associative array containing data on attribute and value
     *	@since PHP4 OOP 0.0.1
     */
    private function combAttributes($attr)
    {
        $attrarr  = array();
        $mode     = 0;
        $attrname = '';

        # Loop through the whole attribute list

        while (strlen($attr) != 0)
        {
            # Was the last operation successful?
            $working = 0;

            switch ($mode)
            {
                case 0:	# attribute name, href for instance
                    if (preg_match('/^([-a-zA-Z]+)/', $attr, $match))
                    {
                        $attrname = $match[1];
                        $working = $mode = 1;
                        $attr = preg_replace('/^[-a-zA-Z]+/', '', $attr);
                    }
                    break;
                case 1:	# equals sign or valueless ("selected")
                    if (preg_match('/^\s*=\s*/', $attr)) # equals sign
                    {
                        $working = 1;
                        $mode    = 2;
                        $attr    = preg_replace('/^\s*=\s*/', '', $attr);
                        break;
                    }
                    if (preg_match('/^\s+/', $attr)) # valueless
                    {
                        $working   = 1;
                        $mode      = 0;
                        $attrarr[] = array(
                            'name'  => $attrname,
                            'value' => '',
                            'whole' => $attrname,
                            'vless' => 'y'
                        );
                        $attr      = preg_replace('/^\s+/', '', $attr);
                    }
                    break;
                case 2: # attribute value, a URL after href= for instance
                    if (preg_match('/^"([^"]*)"(\s+|$)/', $attr, $match)) # "value"
                    {
                        $thisval   = $this->removeBadProtocols($match[1]);
                        $attrarr[] = array(
                            'name'  => $attrname,
                            'value' => $thisval,
                            'whole' => $attrname . '="' . $thisval . '"',
                            'vless' => 'n'
                        );
                        $working   = 1;
                        $mode      = 0;
                        $attr      = preg_replace('/^"[^"]*"(\s+|$)/', '', $attr);
                        break;
                    }
                    if (preg_match("/^'([^']*)'(\s+|$)/", $attr, $match)) # 'value'
                    {
                        $thisval   = $this->removeBadProtocols($match[1]);
                        $attrarr[] = array(
                            'name'  => $attrname,
                            'value' => $thisval,
                            'whole' => "$attrname='$thisval'",
                            'vless' => 'n'
                        );
                        $working   = 1;
                        $mode      = 0;
                        $attr      = preg_replace("/^'[^']*'(\s+|$)/", '', $attr);
                        break;
                    }
                    if (preg_match("%^([^\s\"']+)(\s+|$)%", $attr, $match)) # value
                    {
                        $thisval   = $this->removeBadProtocols($match[1]);
                        $attrarr[] = array(
                            'name'  => $attrname,
                            'value' => $thisval,
                            'whole' => $attrname . '="' . $thisval . '"',
                            'vless' => 'n'
                        );
                        # We add quotes to conform to W3C's HTML spec.
                        $working   = 1;
                        $mode      = 0;
                        $attr      = preg_replace("%^[^\s\"']+(\s+|$)%", '', $attr);
                    }
                    break;
            }

            if ($working == 0) # not well formed, remove and try again
            {
                $attr = preg_replace('/^("[^"]*("|$)|\'[^\']*(\'|$)|\S)*\s*/', '', $attr);
                $mode = 0;
            }
        }

        # special case, for when the attribute list ends with a valueless
        # attribute like "selected"
        if ($mode == 1)
        {
            $attrarr[] = array(
                'name'  => $attrname,
                'value' => '',
                'whole' => $attrname,
                'vless' => 'y'
            );
        }

        return $attrarr;
    }

    /**
     *	This method removes disallowed protocols.
     *
     *	This method removes all non-allowed protocols from the beginning of
     *	$string. It ignores whitespace and the case of the letters, and it does
     *	understand HTML entities. It does its work in a while loop, so it won't be
     *	fooled by a string like "javascript:javascript:alert(57)".
     *
     *	@access private
     *	@param string $string String to check for protocols
     *	@return string String with removed protocols
     *	@since PHP4 OOP 0.0.1
     */
    private function removeBadProtocols($string)
    {
        $string  = $this->RemoveNulls($string);
        $string = preg_replace('/\xad+/', '', $string); # deals with Opera "feature"
        $string2 = $string . 'a';

        while ($string != $string2)
        {
            $string2 = $string;
            $string  =  preg_replace(
                '/^((&[^;]*;|[\sA-Za-z0-9])*)'.
                '(:|&#58;|&#[Xx]3[Aa];)\s*/e',
                '\$this->filterProtocols("\\1")',
                $string
            );
        }

        return $string;
    }

    /**
     *	Helper method used by removeBadProtocols()
     *
     *	This function processes URL protocols, checks to see if they're in the white-
     *	list or not, and returns different data depending on the answer.
     *
     *	@access private
     *	@param string $string String to check for protocols
     *	@return string String with removed protocols
     *	@see removeBadProtocols()
     *	@since PHP4 OOP 0.0.1
     */
    private function filterProtocols($string)
    {
        $string = $this->decodeEntities($string);
        $string = preg_replace('/\s/', '', $string);
        $string = $this->removeNulls($string);
        $string = preg_replace('/\xad+/', '', $string); # deals with Opera "feature"
        $string = strtolower($string);

        if(is_array($this->allowed_protocols) && count($this->allowed_protocols) > 0)
        {
            foreach ($this->allowed_protocols as $one_protocol)
            {
                if (strtolower($one_protocol) == $string)
                {
                    return "$string:";
                }
            }
        }

        return '';
    }


    private function safecss_filter_attr($css){
        $css = $this->removeNulls($css);
        $css = str_replace(array("\n","\r","\t"), '', $css);

        if ( preg_match( '%[\\(&=}]|/\*%', $css ) ) // remove any inline css containing \ ( & } = or comments
            return '';

        $css_array = explode( ';', trim( $css ) );
        $allowed_attr = array( 'text-align', 'margin', 'color', 'float',
            'border', 'background', 'background-color', 'border-bottom', 'border-bottom-color',
            'border-bottom-style', 'border-bottom-width', 'border-collapse', 'border-color', 'border-left',
            'border-left-color', 'border-left-style', 'border-left-width', 'border-right', 'border-right-color',
            'border-right-style', 'border-right-width', 'border-spacing', 'border-style', 'border-top',
            'border-top-color', 'border-top-style', 'border-top-width', 'border-width', 'caption-side',
            'clear', 'cursor', 'direction', 'font', 'font-family', 'font-size', 'font-style',
            'font-variant', 'font-weight', 'height', 'letter-spacing', 'line-height', 'margin-bottom',
            'margin-left', 'margin-right', 'margin-top', 'overflow', 'padding', 'padding-bottom',
            'padding-left', 'padding-right', 'padding-top', 'text-decoration', 'text-indent', 'vertical-align',
            'width' );

        if ( empty($allowed_attr) )
            return $css;

        $css = '';
        foreach ( $css_array as $css_item ) {
            if ( $css_item == '' )
                continue;
            $css_item = trim( $css_item );
            $found = false;
            if ( strpos( $css_item, ':' ) === false ) {
                $found = true;
            } else {
                $parts = explode( ':', $css_item );
                if ( in_array( trim( $parts[0] ), $allowed_attr ) )
                    $found = true;
            }
            if ( $found ) {
                if( $css != '' )
                    $css .= ';';
                $css .= $css_item;
            }
        }

        return $css;
    }




    /**
     *	Controller method for performing checks on attribute values.
     *
     *	This method calls the appropriate method as specified by $checkname with
     *	the parameters $value, $vless, and $checkvalue, and returns the result
     *	of the call.
     *
     *	This method's functionality can be expanded by creating new methods
     *	that would match checkAttributeValue[$checkname].
     *
     *	Current checks implemented are: "maxlen", "minlen", "maxval", "minval" and "valueless"
     *
     *	@access private
     *	@param string $value The value of the attribute to be checked.
     *	@param string $vless Indicates whether the the value is supposed to be valueless
     *	@param string $checkname The check to be performed
     *	@param string $checkvalue The value that is to be checked against
     *	@return bool Indicates whether the check passed or not
     *	@since PHP5 OOP 1.0.0
     */
    private function checkAttributeValue($value, $vless, $checkname, $checkvalue)
    {
        $ok = true;
        $check_attribute_method_name  = 'checkAttributeValue' . ucfirst(strtolower($checkname));
        if(method_exists($this, $check_attribute_method_name))
        {
            $ok = $this->$check_attribute_method_name($value, $checkvalue, $vless);
        }

        return $ok;
    }

    /**
     *	Helper method invoked by checkAttributeValue().
     *
     *	The maxlen check makes sure that the attribute value has a length not
     *	greater than the given value. This can be used to avoid Buffer Overflows
     *	in WWW clients and various Internet servers.
     *
     *	@access private
     *	@param string $value The value of the attribute to be checked.
     *	@param int $checkvalue The maximum value allowed
     *	@return bool Indicates whether the check passed or not
     *	@see checkAttributeValue()
     *	@since PHP5 OOP 1.0.0
     */
    private function checkAttributeValueMaxlen($value, $checkvalue)
    {
        if (strlen($value) > intval($checkvalue))
        {
            return false;
        }
        return true;
    }

    /**
     *	Helper method invoked by checkAttributeValue().
     *
     *	The minlen check makes sure that the attribute value has a length not
     *	smaller than the given value.
     *
     *	@access private
     *	@param string $value The value of the attribute to be checked.
     *	@param int $checkvalue The minimum value allowed
     *	@return bool Indicates whether the check passed or not
     *	@see checkAttributeValue()
     *	@since PHP5 OOP 1.0.0
     */
    private function checkAttributeValueMinlen($value, $checkvalue)
    {
        if (strlen($value) < intval($checkvalue))
        {
            return false;
        }
        return true;
    }

    /**
     *	Helper method invoked by checkAttributeValue().
     *
     *	The maxval check does two things: it checks that the attribute value is
     *	an integer from 0 and up, without an excessive amount of zeroes or
     *	whitespace (to avoid Buffer Overflows). It also checks that the attribute
     *	value is not greater than the given value.
     *
     *	This check can be used to avoid Denial of Service attacks.
     *
     *	@access private
     *	@param int $value The value of the attribute to be checked.
     *	@param int $checkvalue The maximum numeric value allowed
     *	@return bool Indicates whether the check passed or not
     *	@see checkAttributeValue()
     *	@since PHP5 OOP 1.0.0
     */
    private function checkAttributeValueMaxval($value, $checkvalue)
    {
        if (!preg_match('/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value))
        {
            return false;
        }
        if (intval($value) > intval($checkvalue))
        {
            return false;
        }
        return true;
    }

    /**
     *	Helper method invoked by checkAttributeValue().
     *
     *	The minval check checks that the attribute value is a positive integer,
     *	and that it is not smaller than the given value.
     *
     *	@access private
     *	@param int $value The value of the attribute to be checked.
     *	@param int $checkvalue The minimum numeric value allowed
     *	@return bool Indicates whether the check passed or not
     *	@see checkAttributeValue()
     *	@since PHP5 OOP 1.0.0
     */
    private function checkAttributeValueMinval($value, $checkvalue)
    {
        if (!preg_match('/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value))
        {
            return false;
        }
        if (intval($value) < ($checkvalue))
        {
            return false;
        }
        return true;
    }

    /**
     *	Helper method invoked by checkAttributeValue().
     *
     *	The valueless check checks if the attribute has a value
     *	(like <a href="blah">) or not (<option selected>). If the given value
     *	is a "y" or a "Y", the attribute must not have a value.
     *
     *	If the given value is an "n" or an "N", the attribute must have one.
     *
     *	@access private
     *	@param int $value The value of the attribute to be checked.
     *	@param mixed $checkvalue This variable is ignored for this test
     *	@param string $vless Flag indicating if this attribute is not supposed to have an attribute
     *	@return bool Indicates whether the check passed or not
     *	@see checkAttributeValue()
     *	@since PHP5 OOP 1.0.0
     */
    private function checkAttributeValueValueless($value, $checkvalue, $vless)
    {
        if (strtolower($checkvalue) != $vless)
        {
            return false;
        }
        return true;
    }

    /**
     *	Decodes numeric HTML entities
     *
     *	This method decodes numeric HTML entities (&#65; and &#x41;). It doesn't
     *	do anything with other entities like &auml;, but we don't need them in the
     *	URL protocol white listing system anyway.
     *
     *	@access private
     *	@param string $value The entitiy to be decoded.
     *	@return string Decoded entity
     *	@since PHP4 OOP 0.0.1
     */
    private function decodeEntities($string)
    {
        $string = preg_replace('/&#([0-9]+);/e', 'chr("\\1")', $string);
        $string = preg_replace('/&#[Xx]([0-9A-Fa-f]+);/e', 'chr(hexdec("\\1"))', $string);
        return $string;
    }

    /**
     *	Returns PHP5 OOP version # of kses.
     *
     *	Since this class has been refactored and documented and proven to work,
     *	I'm fixing the version number at 1.0.0.
     *
     *	This version is syntax compatible with the PHP4 OOP version 0.0.2.  Future
     *	versions may not be syntax compatible.
     *
     *	@access public
     *	@return string Version number
     *	@since PHP4 OOP 0.0.1
     */
    public function Version()
    {
        return 'PHP5 OOP 1.0.2';
    }
}